UBC undergrad-astronomy student Michelle Kunimoto holds a celestial sphere, showing the stars as they appear in our skies. She has added four new planets to the map of the sky, including a system that might be an abode for life.

When Michelle Kunimoto tosses her mortarboard into the sky Monday, perhaps it will spin toward the four planets she just discovered.

Kunimoto, 22, should feel proud of the four years she spent at the University of B.C. gazing at stars. Not many undergrads can say they’ve tracked down unknown celestial bodies.

She said her yearning to study the Milky Way began during the astronomy section of a Grade 9 science class and soon after her dad came home with a box set of Star Trek: The Original Series.

A proud Trekkie, Kunimoto embarked on her own mission to explore strange new worlds and to seek out new life, but as a physics and astronomy student toting a laptop, rather than as a science officer aboard a starship.

“I was always just fascinated, you know, if you look up at the sky, what, exactly, is out there?” said Kunimoto, whose research focuses on planetary habitability and exoplanets, the planets beyond our solar system. “The search for life is really exciting, but there’s also just so much that we don’t know about our universe and about our own planet.”

This past year, she spent months sifting through 400 light curves — measurements of the brightnesses of stars versus time — from data collected by NASA’s planet-seeking Kepler spacecraft.

NASA’s team had already found hundreds of exoplanets and dozens of false alarms in this data, which Kunimoto independently rediscovered.

But she also found 23 new signals and narrowed those down to four new planet candidates— two Earth-sized, one Mercury-sized and one slightly larger than Neptune.

Kunimoto said she did this by looking deeper through signals picked up by Kepler, and seeking planets hidden among the noise. Usually, signals below a signal-to-noise ratio of 7.1 are dismissed as “false positives.” Kunimoto expanded upon NASA’s search by lowering that ratio to six, she said.

The fourth Neptune-sized planet, called KOI (Kepler Object of Interest)-408.05, has her most excited. It orbits within its star’s habitable “Goldilocks” zone, where the temperature is between the boiling and freezing points of water.

Kunimoto spent a whole summer combing through the Kepler data without turning any up. But while working on another project and waiting for her computer to run some code, she returned to the data. Thrilled by her discovery, she delivered the good news to her supervising professor, Jaymie Matthews of UBC’s Department of Physics and Astronomy.

“Michelle is a big Star Trek fan, but in this case, she’s not going boldly where no one has gone before,” Matthews said. “She’s actually going boldly where lots of NASA experts have been before, to find things that they’ve missed.”

The four new planet candidates, shown to scale beside the planets Mercury, Earth and Neptune.Michelle Kunimoto and Jaymie Matthews (UBC)

Matthews said he and Kunimoto are being “good, conservative” scientists by referring to the four planets as “candidates” before they’re verified.

“But they’re extremely convincing and that’s why we’re willing to go out to announce them, so that others can follow up on them,” he said.

Matthews said KOI-408.05 is likely uninhabitable, but he’s almost certain a planet of its size would have moons that could be home to liquid oceans. Maybe even life.

“Basically, Michelle has found a place … that at least checks off a few of what we consider necessary, but not sufficient, requirements for life as we know it,” Matthews said. “I can guarantee you that the people in SETI — the search for extraterrestrial intelligence — will be focusing their attention on this as they have on the other planets in the habitable zones, to eavesdrop, to see if there are any signals coming out of there.”

Jaymie Matthews, professor at the University of B.C.’s Department of Physics and Astronomy, is glowing with pride at student Michelle Kunimoto’s discovery of four planet candidates.Martin Dee for UBC

Kunimoto’s discoveries have earned her praise from her peers. But they also earned her a chance to meet the man behind Captain James T. Kirk himself, when William Shatner visited UBC on Saturday to give a talk called “The Curious Life.”

“It was a real honour to meet him,” said Kunimoto Sunday, adding that she had Shatner sign her Star Trek DVD. “He actually made a shout out to my work during the question and answer period. That was the stuff of my dreams!”

Kunimoto’s research paper, co-authored by Matthews, his former PhD student Jason Rowe and fellow grad student Kelsey Hoffman, has been submitted to The Astronomical Journal.

Wednesday, Kunimoto heads to McGill University in Quebec to spend the summer researching exoplanets. She’ll return to UBC in the fall to pursue her Master’s degree in astronomy.

Her parents are proud she’s found her calling in the stars.

“And I know my dad is extremely jealous about me meeting William Shatner,” she said with a laugh.

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